What is glaucoma?

Glaucoma is a serious eye condition that can cause blindness. It damages the optic nerve, which carries information from your eyes to the visual center in your brain. This damage can result in permanent vision loss.

The most common type of glaucoma has no early warning signs and can only be detected during a comprehensive eye exam. If undetected and untreated, glaucoma first causes peripheral vision loss and eventually can lead to blindness.

By the time you notice vision loss from glaucoma, it’s too late. The lost vision cannot be restored, and it’s very likely you may experience additional vision loss, even after glaucoma treatment begins.

The only way to protect yourself and your family from vision loss and even blindness from glaucoma is to visit an eye doctor for routine comprehensive eye exams.

Only an optometrist or ophthalmologist is trained to spot the early warning signs of glaucoma and to begin glaucoma treatment before vision loss occurs.

What causes glaucoma?

In most cases, glaucoma is caused by higher-than-normal pressure inside the eye — a condition called ocular hypertension.

But sometimes glaucoma can occur even when pressure inside the eye — called intraocular pressure or “IOP” — is normal.

Illustration of glaucoma
In most types of glaucoma, optic nerve damage and vision loss occurs because the pressure inside the eye (IOP) is too high.

A quick review of eye anatomy will help describe what causes glaucoma:

The space between the clear front surface of the eye (the cornea) and the lens inside the eye is filled with a clear fluid called the aqueous humor. This fluid nourishes the inside of the anterior part of the eye. It also maintains the shape of the eye by keeping the eyeball properly pressurized.

The aqueous humor is constantly being produced by a structure called the ciliary body that surrounds the lens, and it drains from the eye through a mesh-like channel called the trabecular meshwork that’s located in the angle formed inside the eye where the cornea and iris meet.

If something causes this “drainage angle” to close down or the trabecular meshwork to become clogged, the aqueous humor cannot drain from the eye fast enough, and pressure inside the eye (IOP) increases.

Glaucoma usually occurs when too much pressure inside the eye causes damage to the optic nerve at the back of the eyeball, leading to permanent vision loss.

Recent studies also have implicated low intracranial pressure (the pressure that surrounds the brain) as one of the risks for glaucoma.

Glaucoma symptoms

Most types of glaucoma typically cause no pain and produce no symptoms until noticeable vision loss occurs.

This is one reason why routine eye exams are so important — typically, an eye exam is the only way to detect glaucoma before permanent vision loss occurs.

However, a less common type of glaucoma — called acute angle-closure glaucoma — causes sudden, often severe symptoms of blurry vision, halos around lights, eye pain, nausea and vomiting.

If you experience these symptoms, see our office immediately so steps can be taken to reduce your IOP, alleviate symptoms and prevent permanent vision loss.


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